1. Field of the Invention
The present invention relates to an encapsulated window ready for mounting by adhesive bonding in the bay of a body.
2. Description of the Background
Mounting windows for motorized vehicles by adhesive bonding in the bay of a vehicle body has several advantages, namely; it ensures the position maintenance of the window in the bay of the body in the event of violent shock; it can be automated; and it permits the window to be fitted flush in the body, thereby reducing the penetration coefficient of the vehicle in the air.
When mounting a one-piece or laminated window not incorporating a duplicate-molded profile, adhesive bonding of the window in the body bay is achieved by depositing a suitable adhesive strip on an enameled edge provided on the periphery of the surface of the window turned toward the passenger compartment. This enameled edge is designed, in particular, to protect the adhesive from UV radiation, which might damage its properties. It also serves an aesthetic function by hiding an unsightly glue joint.
When the window is encapsulated, i.e., when it is provided with a duplicate-molded peripheral profile (or encapsulation joint) designed, in particular, to replace the finishing joint, mounting of the window by adhesive bonding may be achieved as in the mounting of previous windows, i.e., by bonding on the glass or an enameled edge at the boundary of the duplicate-molded profile. In one variant, bonding may take place directly on the duplicate-molded profile. However, in this variant the bond obtained using conventional glue joints is not satisfactory, since the adhesive forces are generally insufficient or are not preserved over time.
This poor adhesion may result from the presence on the duplicate-molded profile of a residue of the unmolding product, which may be used during the manufacture of an encapsulation joint, especially one made of polyurethane, for the purpose of preventing the duplicate-molded profile from being glued to the mold during its fabrication. When the encapsulated window is removed from the mold, some of the unmolding product is left on the profile, and even cleaning with various types of solvents does not make it possible to obtain satisfactory bonding properties. Poor adhesion may also result, in particular when a profile is duplicate molded using polyvinyl chloride (PVC), from stabilization agents used to combat the effects of light, or from plasticizers which may be incorporated, as needed, into the material used to form the profile.
European Patent Publication EP 0 378 462 describes an encapsulated window ready for installation and which possesses a bonding capacity meeting the safety standards for windows.
The encapsulated window described EP 0 378 462 is a one-piece or laminated window containing, on its periphery, a duplicate-molded profile (or encapsulation joint), one surface of which is designed to be glued in a bay of a body, such as the bay of the body of a motorized vehicle, e.g. by means of an adhesive strip, said surface being reactive since it contains free OH groups capable of reacting subsequently with the adhesive strip used for mounting the window in the bay.
The solution proposed in EP 0 378 462 is entirely satisfactory, for a window fitted with a polyurethane-based duplicate-molded profile. This profile can be produced by RIM (reaction injection molding) or by thermoplastic injection.
However, in the case of a duplicate-molded profile made of polyvinyl chloride (PVC), the recommended solution does not afford satisfactory results. In particular, adhesive bonding of this duplicate-molded profile with polyurethane mastics currently used for gluing windows in body bays may prove insufficient from the beginning, or this bond may not be sufficiently preserved over time.
Thus, a need exists for a window which is ready for mounting and having adhesive bonding in a body bay which is strong at the outset and which is also preserved over time.